Comparison of the effect of subcutaneous progesterone and vaginal progesterone for luteal phase support

Objective: It was aimed to examine pregnancy rates by comparing the efficacy of subcutaneous and vaginal progesterone for luteal phase support in gonadotropin-induced IUI (intrauterine insemination) cycles. Methods: The study was conducted in Bezmialem Vakıf University Hospital between April 2022 and June 2022 as a prospective randomized controlled study. Patients who underwent IUI due to unexplained infertility, anovulation and mild male factor were included in the study. In total, 146 patients were randomized into two groups. From the first day after insemination, patients received intravaginal progesterone (LUTINUS® 100 mg vaginal tablet, Ferring GmbH Wittland/Kiel/Germany) once a day in group 1, subcutaneous progesterone in group 2 (PROLUTEX® 25 mg Injectable Solution, IBSA Group, Lugano, Switzerland) from the first day after insemination was given once a day. Pregnancy rates were recorded by performing a blood pregnancy test on the 15th day after the procedure. At the end of the study, betahCG positivity, biochemical pregnancy, clinical pregnancy and ongoing pregnancy rates of the patients were compared. Results: A total of 137 patients underwent IUI. As a result of the study, no statistically significant difference was observed between the groups in terms of demographic data, sperm parameters and cycle characteristics. When the pregnancy outcomes of the patients were examined, the rates of clinical pregnancy and ongoing pregnancy were higher in the group that received luteal phase support with vaginal progesterone compared to subcutaneous progesterone [RR 2.63; 95% CI, 1.26–5.49; p=0.011 and RR 2.87; 95% CI, 1.21–6.79; p=0.019]. There was no significant difference between the groups in terms of biochemical pregnancy and missed abortion rates [RR 0.63; 95% CI, 0.18–2.16; p=0.690 and RR 1.91; 95% CI, 0.36–10.1; p=0.718] Conclusion: Vaginal progesterone for luteal phase support in gonadotropin-induced IUI cycles provides a significantly higher clinical pregnancy and ongoing pregnancy rate than subcutaneous progesterone. Keywords: iui, luteal phase support, vaginal progesterone, subcutaneous progesterone